Preparation of amino azole disulfides



2,850,496 i atented Sept. 2, 1958 United tat atent ice The amine monosulfides can be represented by the structural formula 2,850,496 PREPARATION OF ANHNQ AZOLE DISULFIDES 5 \N S N/ Albert E. Hardman, Northampton Township, Summit County, Ohio, assignor to The Goodyear Tire & Rubber Company Akron a corporation of 81m in which the Rs are the same or different aliphatic radi- No Drawing. Application September 23,1954 l0 cals, cycloaliphatic radicals, or aralkyl radicals or in Serial No. 458,627 which the pair of Rs on a nitrogen atom are joined to 1 Claim. (CL 260*247'1) form a single ring. Thus, included are the amine monosulfides 1n which the two Rs on a mtrogen atom are a closed chain, which can be interrupted by sulfur, oxygen or an imino group NH).

Representative amine monosulfides are the bis secondary amine monosulfides such as This invention relates to amino azole disulfides and to a method of making these materials.

Amino azole disulfides are powerful accelerators of vulcanization of rubber. They can be used to promote N Nz hi j (di h i the curing of rubber with or without sulfur. These ma- N (diethylamine) terials are particularly useful in black tread stocks and (di n pmpylamine) other compositions containing rubber in which a power- NZNLthiObiS (dimbmylamine) ful, yet delayed action, non-scorching accelerator is needed to promote the curing of the rubber.

The compounds with which this invention is concerned are the secondary amino azole disulfides. These compounds have the following general structure:

N,N'-thio-bis-diisobutylamine N,N'-thio-bis-di-n-amylamine N,N-thio-bis-diisoamylamine N,N'-thio-bis-di-n-hexylamine N ,N-thio-bis-di-n-heptylamine N,N'-thio-bis-di-n-octylarnine N,N'-thio-bis-dibenzylamine R1 N,N'-thio-bis-methylcyclohexylamine in which R and R are the same or different aliphatic, J? i l y Y l Y cycloaliphatic or aralkyl groups or R and R may top gether form a single chain or ring and R represents a N,N-thio-bis (thiomorpholine) member of the class consisting of thiazoles, oxazoles and N,N-thio-bis (4-N-ethyl piperazine) imidazoles. N,N'-thio-bis (piperidine) According to this invention amino azole disulfides are N N'-thio-b (Py prepared by reacting an amine monosulfide with an azyl I disulfide. The reaction appears to proceed according to NM 'thlo'bls (mmphoune) and NN 'thlo'bls (d1 Satu' the following equation in Whish morphofine monosulfide rated straight chain amines) are preferred species. and 22-1 1 (benzmhiazyl) di ulfid are used as 40 The azyl disulfides which can be used include the thi- The practice of the invention is illustrated by the folfides. Both aromatic and aliphatic azyl disulfides can be lowing representative example. used. Representative examples are:

EXAMPLE 2,2-bis (thiazyl) disulfide 2,2'-bis (oxazyl) disulfide Preparation of 2-(4-morpholmyldzthz0) benzothzazole 224m (imidazyl) disulfide Two and twenty-seven one hundredths grams of N,N- 2,2'-bis r-methyl thrazyl) drsulfide bis (morpholine) monosulfide, 3.65 grams of 2,2'-bis i (4rn hy1 exazyl) s llfid (benzothiazyl) disulfide, 1 gram of morpholine, as a cata- 2,2'-bis l-methyl rmrdazyl) drsulfide lyst, and 10 milliliters of methanol were placed in a 2, y y d 151l1fid6 small flask set up with a reflux condenser and stirrer. 2,2'-bis (4-ethyl oxazyl) drsulfide The mixture was refluxed for one hour and cooled. The 2,2bis l-ethyl imida zyl) drsulfide solid portion was separated by filtration and washed with 2,2'bis (4-n-propyl thiazyl) d sulfide methanol. A yield of 3.1 grams of 2-(4-morpholinyldi- 2,2-bis (4n-propyl oxazyl) drsulfide thio) benzothiazole was obtained. From the methanol 2,2'-bis (4-n-propyl imldazyll dlSlllfldB filtrate, 2.3 grams of a second product identified as N-oxy- 2,2-bis (4-n-butyl thrazyl) d sulfide diethylene-Z-benzothiazole-sulfenamide was obtained. 2,2'-bis (4-n-butyl oxazyl) drsulfide Various other amino azole disulfides can be prepared 2,2'-bis (4-n-butyl inudazyl) drsulfide by using other amine monosulfldes and other azyldisul- 2,2-b is (4,5-d imethyl thrazyl) drsulfide fides in place of those shown in the above example. 2,2-b1s (4,5-d1methyl oxazyl) drsulfide 2,2-bis (4,5-dimethyl imidazyl) disulfide 2,2'-bis (4,5-diethyl thiazyl) disulfide 2,2'-bis (4,5-diethyl oxazyl) disulfide 2,2'-bis (4,5-diethyl imidazyl) disulfide 2,2-bis (4,5-di-n-propyl thiazyl) disulfide 2,2-bis (4,5-di-n-propyl oxazyl) disulfide 2,2'-bis (di-n-propyl imidazyl) disulfide 2,2'-bis (4-phenyl thiazyl) disulfide 2,2-bis (4-phenyl oxazyl) disulfide 2,2-bis (4-phenyl imidazyl) disulfide 2,2'-bis (4-phenyl-5-methyl thiazyl) disulfide 2,2' bis (4-phenyl-5-methyl oxazyl) disulfide 2,2'-bis (4-phenyl-S-methyl imidazyl) disulfide (4-phenyl benzothiazyl) disulfide 2,2-bis (4-phenyl benzoxazyl) disulfide 2,2-bis (4-phenyl benzimidazyl) disulfide 2,2-bis (4-chloro benzothiazyl) disulfide 2,2'-bis (4-chloro benzoxazyl) fdisulfide 2,2"-bis (4-chloro benzimidazyl) disulfide 2,2'-bis (6-chloro benzothiazyl) disulfide 2,2-bis (6-chloro benzoxazyl) disulfide (6-chloro benzimidazyl) disulfide (benzothiazyl) disulfide (benzoxazyl) disulfide (benzimidazyl) disulfide (tetrahydro benzothiazyl) disulfide (tetrahydro benzoxazyl) disulfide (tetrahydro benzimidazyl) disulfide (naphthothiazyl) disulfide 2,2-bis (naphthooxazyl) disulfide 2,2'-bis (naphthoimidazyl) disulfide The benzothiazyl disulfides and particularly 2,2'-.bis (benzothiazyl) disulfide are preferred materials.

In preparing these materials solvents may be present, and it is generally preferable to use an amine catalyst to speed up the reactions. Solvents which have been found 2,2-bis 2,2'-bis 2,2-bis 2,2-bis 2,2'-bis 2,2-bis 2,2-bis to be suitable for use in this process are the lower aliphatic alcohols such as methanol, ethanol, isopropanol, normal propanol and normal butanol. Amines which have been found to be effective catalysts are morpholine, cyclohexylamine, and, in general, the amine corresponding to the amine radical of the amine sulfide used in the reaction.

The reaction of the above example was carried out at the reflux temperature of the mixture. Other temperatures can be used, with appropriate adjustment of the time of reaction. The temperature is not critical, but it is desirable to use a temperature that will give reasonably fast reaction rates so that the process may be economically carried out. For most eflicient use of the reactants one mol of the amine monosulfide is used to one mol of the azyl disulfide, although other proportions can he used, if desired.

While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in this art that various changes and modifications may be made therein without departing from the spirit or scope of the inven-- tion.

I claim:

The method of preparing 2-(4-morpholinyl dithio) benzothiazole which comprises reacting N,N'-bis(mor pholine)monosulfide with 2,2'-bis(benzothiazyl)disulfide in the presence of morpholine, as a catalyst,;in methanol at reflux temperature of the mixture, cooling the mixture and separating the 2-(4-morpholinyl dithio)benzothiazo1e formed and recovering N-oxydiethylene-Z-benzothiazole' sulfenamide from the filtrate.

References Cited in the file of this patent UNITED STATES PATENTS UNITED STATES PATENT OFFICE H CERTIFICATE OF GORRECTION Patent N00 2,850,496 September 2, 1958 Albert F0 Herdmen It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 72, after "example" and before the period insert 5 2%di n propylaminodithio)benzothiazole by reacting N,N-=thio-=bis (di=-n=-propylamine) with 2 2 =bie((benzothiazyl) dieulficle; 2=(di=n=- butylaminodithio)benzothiazole by reacting =thio==his (di=n=butylamine) with 2,2 -=bis(benzothiazyl)disulfide; and 2==llpigaeridyldithio henzothiazole by reacting N,N =thio=bis(piperidine) with 2,2 =-bis(benzothiazyl)disulfide Signed and sealed this 23rd day of D cember 19580 SEAL) ttest:

KARL 1 AXIINE ROBERT c. WATSON Attesting Oflicer Commissioner of Patents 

